In the processing of semiconductor devices, such as transistors, diodes and integrated circuits, a plurality of semiconductor devices are fabricated simultaneously on a thin slice of semiconductor material called semiconductor “device” wafer or electronic device wafer. Such a semiconductor wafer may be thin enough to be susceptible to warpage due to thermal changes. Thus, during the manufacturing of semiconductor integrated circuits, care should be taken to enable handling of highly warped wafers (e.g., wafers being impacted by cooling) without damage to the wafer.
Various known techniques enable the handling of device wafers without human intervention. Some known wafer handling devices make use of a “vacuum” or gas flow generated holding force to hold (e.g., “grip”) the wafer without contact with a pickup surface of the device. However, such non-contact holding may result in possible damage at room temperature due to increased warpage of the wafer, particularly when wafer thickness is reduced.
For example, prior to dicing a device wafer into separate die or chips, the device wafer may be separated or “debonded” from a carrier upon which it is bonded, along a layer of adhesive that bonds the wafers. In some cases, a debonding operation is carried out to separate the device wafer from the carrier through thermal slide mechanism to slide the wafers apart laterally along the adhesive. After debonding, a non-contact wafer handling gripper or chuck may be used to handle the wafer using gas emitting pods (such as divergent or vortex nozzle type emitting pods) to create low pressure regions (e.g., below atmospheric pressure) at the surface of the wafer, which provide a holding force.
However, some wafers may experience warpage during or after handling by the gripper. Therefore, there exists a need for handling semiconductor wafers while substantially minimizing warpage of device wafers being handled after debonding from a carrier, and during cleaning of the bonding adhesive from thin device wafers.